His death came amid a rise in violence and separatist sentiment across the state, which has been at the centre of a tussle between India and Pakistan for decades.

The director general of Jammu and Kashmir police, K Rajendra Kumar, told reporters that 100 members of the security forces had been wounded and that three were missing.

In addition, "miscreants threw a police vehicle into River Jhelum", south of the state's summer capital of Srinagar, killing the officer inside, he said.

On Saturday, police had said that angry crowds set fire to three police stations and two government buildings south of Srinagar, and blocked roads.

Mr Kumar put the protestor death toll at 15, but a second officer, who asked to remain anonymous, said four more died on Sunday in clashes with security forces, raising the total number of deaths to 20.

Confrontations continued on Sunday despite the authorities imposing round-the-clock curfew conditions on most of the Kashmir valley, the officer said.

Wani was the leader of Hizb-ul Mujahideen, a group fighting Indian control of the Muslim-majority region. His social media videos show him wearing military fatigues and calling for jihad.

Activists and separatist leaders have criticised the security forces' response to the protests, accusing them of using excessive force.

"It is shocking and painful that Indian armed forces have yet again unleashed terror on the mourners and protesters, resulting in massive civilian casualties," Khurram Parvez, an activist with rights group the Jammu and Kashmir Coalition for Civil Society, said in a statement.

The local government has appealed to the public and separatist political leaders to help calm the situation.